It is known to treat timber whereby to transform its appearance such that it resembles another type of wood. For example, U.S. Patent Application Publication 2002/0178608 A1, published on Dec. 5, 2002, describes a method and an apparatus for treating wood whereby it resembles Bog oak. The method is a chemical method which involves a sequence of steps under controlled conditions of time, temperature and pressure and in particular, a steam-air-ammonia composition is added to the timber. It can treat a wide variety of wood types to resemble Bog oak and depending on the specific type of wood used, the process is modified. The wood is treated under pressure within an appropriate vessel which is constructed for this treatment and the wood can be introduced therein in a dry or green state but is always treated with the ammonia composition. The aim of that process and apparatus is to change the quality of the treated timber to resemble Bog oak timber which is a higher quality timber. However, that system is quite expensive and is potentially not friendly to the environment. The timber is also treated in a reactor under pressure and ammonia is blown therein, which process could be hazardous to work personnel. Accordingly, many precautions need to be taken when this timber is manipulated in and out of the reactor. By using high and low pressures, there are risks of explosion and by using toxic products at high pressures the reactor must be constructed of expensive material, such as stainless steel. The process as described in this patent transforms in a radical fashion the properties of the treated timber, such as increasing the hardness of the timber whereby the planing and sawing thereof causes more wear-and-tear on machinery. The timber also is subjected to a change of its hygroscopic properties thereby requiring a different drying process. Accordingly, not only is the process more costly, but the processing of the treated timber provides an additional cost.
When drying wood at high temperature, such as betula, the object is to extract water from the wood as quickly as possible. Accordingly, the wood is dried under conditions that favour evaporation to reduce the humidity within the wood down to about 6% to 12% (percent). When betula is dried at high temperature, its coloration changes to the brownish tones, sort of a caramel color. This coloration change is not adding value to Birch wood and is mostly considered as a defect of drying. It is known that this drying process will cause great stress in the wood causing many drying defects such as checks, splits and loose knots.